Kjaergaard rode with Armstrong in the U.S. Postal Service team when the American won the Tour de France in 2000 and 2001. He said he wasn’t aware of any of his teammates using banned substances, “but I assume there were others.”

On Monday, Armstrong was stripped of his seven Tour de France titles by the International Cycling Union after the U.S. Anti-Doping Agency detailed evidence of drug use and trafficking by his Tour-winning teams.

“I have not directly witnessed anyone else dealing with this. That’s why I do not want to expose anyone else,” Kjaergaard said.

Kjaergaard won several Norwegian championships but no major international races before retiring in 2003.

His admission dented Norway’s self-image as a “clean” nation in the forefront of the fight against doping in sports. Kjaergaard was removed from his job as sports director for the Norwegian Cycling Federation.

“This is a sad day for Norwegian cycling, but we wanted to have this out in the light,” said federation President Harald Tiedemann Hansen at the joint news conference with Kjaergaard.

“He has admitted to doping and he has nothing to do with the cycling world anymore,” Tiedemann Hansen told The Associated Press. “He has been suspended until his term ends on Dec. 31 and he will not continue in the job.”